How to Fix Your Mercedes-Benz GL450 Suspension Problems the Right Way

How to Fix Your Mercedes-Benz GL450 Suspension Problems the Right Way

Troy Hammond
7 minute read

Are you having trouble with your Mercedes-Benz GL450 air suspension? You've come to the right place. The air suspension in your Mercedes-Benz GL450 gives the German luxury vehicle a smooth, cloud-like ride. However, years of driving can cause wear and tear. Knowing how to get your vehicle in peak condition starts with learning about common air suspension malfunctions. This guide will teach you how to diagnose and repair air suspension issues. You'll also learn a cost-effective way to restore your vehicle without compromising quality.

Mercedes GL450 Air Suspension Malfunction

Typical Mercedes GL450 front and rear air suspension problems include the following.

1. Air Suspension Compressor Failure

The air suspension compressor generates compressed air to keep the vehicle running smoothly. Over time, this component may malfunction due to a burned-out motor or cracked suspension lines, reducing pumping speed or causing complete stoppage. As a result, the air suspension may be unable to maintain its proper level. Your vehicle might sag in the front or rear, causing unevenness that makes the ride bouncier. In extreme cases, your Mercedes could become undriveable.

2. Faulty Relay 

The suspension compressor relay may keep the air suspension compressor engaged longer than required or prevent it from engaging altogether. When kept engaged for too long, the compressor relay may get damaged. A common symptom is that the air suspension may fail to inflate and deflate properly or the system may make strange noises. Short circuits, electrical faults or broken wires may cause a faulty relay. You may need to replace the relay, clean the contacts or repair the wiring to fix this problem.

3. Blown Fuse

A blown fuse may cause your suspension to malfunction, affecting your vehicle's ability to adapt to different conditions. Common symptoms include bouncier rides, poor handling and uneven tire wear. If you check the fuse and find out it has blown, replace it with a new one with the same amperage. If the problem persists, you may have to check the air springs or suspension compressor. When you replace the fuse, but it keeps blowing, you might have a problem with the air compressor motor or pump.

4. Leaky Struts

The lines that supply compressed air to the strut may develop cracks and eventually cause the air to leak, which may result in your vehicle leaning over or tilting to one side. While fixing this problem is relatively simple and affordable, it is crucial to do so immediately. 

5. Valve Block Leaking

A damaged seal or a faulty O-ring may cause a solenoid valve block leak. The best way to fix this problem is by first diagnosing your Mercedes GL450 air suspension.

The solenoid valve could leak air into the central air reservoir or the compressor, making it difficult for your Mercedes to maintain the required height. The suspension becomes softer and bouncier than usual, and the vehicle will sag on one side. A damaged seal or a faulty O-ring may cause a solenoid valve block leak. The best way to fix this problem is by first diagnosing your Mercedes GL450 air suspension. The mechanic may check the pressure in the system and look for signs of leakage. Once they identify the leak, they may replace the seal, faulty O-ring or all affected parts.

6. Faulty Level Sensor

The level sensors are near the front and rear suspension. The air suspension control unit may not calibrate the height when it malfunctions. A warning sign may show on the dashboard to alert you of the AirMatic failure.

Diagnosing Mercedes GL450 Air Suspension Issues

Air suspension issues manifest themselves in different ways. Some might see evidence of suspension failure from the outside. One typical example is the car sagging low in the rear. You might also find your GL450 leaning to one side. Sometimes owners can hear the evidence. If the compressor runs too loudly or too long, it’s a sign that it’s working too hard, which indicates a suspension fault somewhere in the system. You might also feel that difference.

A car driving on bad struts will take much longer to stop. When it does, it often dips forward into a “nose dive,” with the back popping up, looking like it is crouching. Mercedes also included a suspension warning light that will illuminate when there is a problem. However, this might come later than some of the physical symptoms. If you notice any of these symptoms in your Mercedes-Benz GL450, it is time to have your suspension serviced. 

Repairing Your Mercedes-Benz GL450 Air Suspension

If your suspension problems took you to the dealership, they likely recommended replacing the broken air suspension components — probably accompanied by a repair quote that made you do a double-take. The reality is that air suspensions are highly complex and, therefore, expensive systems. 

Mercedes air suspensions rely on a web of interconnected parts working together to function correctly. Your Mercedes-Benz GL450 has ride height sensors at each wheel. These sensors signal the control module, letting it know how much to inflate or deflate the airbags. Then, the control module sends this information to the compressor.

The compressor pushes air into the airbags. These rubber sacks suspend your car off its wheels. Each of these components is highly specialized. Many are moving parts, electronic parts or parts made with flexible materials. These are all prone to failure. 

These parts may be expensive to replace because they are labor-intensive and complicated to install.

Mercedes GL450 Air Suspension Repair Costs

Here is how much it might cost to repair your Mercedes GL450 air suspension.

OEM Replacement Cost

OEM replacement costs are as follows.

  • Front air struts with an active dampening system: $1,080 per strut
  • Rear air struts with an active dampening system: $556 per strut
  • Air compressor assembly: $420
  • Pressure accumulator with an active dampening system: $300
  • Total cost without replacing electronic components such as height sensors: over $3,900

Aftermarket Replacement Cost

Aftermarket replacement costs are as follows.

  • Front air struts with an active dampening system: $650 per strut
  • Rear air struts: $680 per strut
  • Air compressor assembly: $490
  • Pressure accumulator: $230
  • Total cost without replacing electronic components such as height sensors: over $3,300

Other Options for Your Mercedes-Benz GL450

At Strutmasters, we sell a conversion kit that lets you kiss your recurring suspension problems goodbye forever. Instead of a mess of electronics and tiny moving components, these traditional coilover suspensions use mechanical resistance to hold your car up. Our durable coilover struts are an excellent alternative to unreliable air suspensions. You can save thousands of dollars versus replacing your suspension with OEM or third-party air suspension parts. 

Strutmasters' suspension conversion kits are so simple that the average DIYer can install one at home with standard tools. No computers, sensors or airbags — just stainless steel and a few high-grade rubber bump stops. Even if you don’t install your suspension conversion kit at home, the ease of installation translates directly to a lower shop bill at your mechanic. But the financial benefits don’t stop there. Each Strutmasters air-to-spring conversion kit for your Mercedes-Benz GL450 has a one year guarantee.

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Ready to Make the Switch? Shop Now

If your Mercedes-Benz GL450 is experiencing suspension failure, converting to a coilover system is the logical choice. Not only will you save money, but you’ll also never have to deal with the constant repairs of an air suspension again. Browse our site for Mercedes GL450 coil spring conversion kits. Feel free to contact us with any product-related questions.

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